Whether solving the problem in a commercial establishment or a domestic home environment, the majority of search results pointed to one solution. Namely, soapy water!
Before they all ridicule the idea as belonging to a bygone era, take a vehicle with a slow puncture to a tyre fitting depot and the chances are they remove the wheel and spin it in water to determine the leak. It’s a simple time-proven method for determining leaks from pressurised systems.
